This invention relates to golf balls and specifically to multi-component golf balls.
Conventional golf balls can be divided into two general types of balls, a two-piece ball and a three-piece ball. The difference in play characteristics resulting from these different types of balls can be significant.
Two-piece balls are generally more popular with the recreational golfers because they provide a very durable ball while also providing maximum distance. Two-piece balls are made with a single solid core, usually made of a crosslinked rubber, which is encased by a cover material. The combination of the core and cover materials provides a hard ball that is virtually indestructible by golfers. Further, such a combination imparts a high initial velocity to the ball which results in improved distance. However, because these materials are very rigid, two-piece balls have a hard feel when struck with a club.
Three-piece or wound balls are preferred by more advanced players due to their superior feel characteristics. Three-piece balls typically have either a solid rubber or liquid center core around which many yards of a stretched thread or yard are wound. The wound core is then covered with a durable cover material. Three-piece balls are generally softer and provide more spin, which enables a skilled golfer to have more control over the ball""s flight. This higher spin characteristic however can be a problem with those who are not advance players as the high side spin rate causes the ball to deviate from a straight path. Furthermore, these higher spinning balls typically have a shorter distance as compared with two-piece balls.
In the past golf balls have been designed which attempt to provide a three-piece ball""s feel while simultaneously providing a two-piece ball""s distance. U.S. Pat. No. 5,984,805 discloses a golf ball having a solid core surrounded by a cavity and an outer layer. The cavity is filled with a liquid so that the outer layer is separated from the solid core by the layer of liquid. This type of golf ball is designed so that the outer layer moves independently of the core to create a gyro moment. The gyro moment stabilizes the spin rate of the golf ball during flight. However, as the ball is struck with a club the ball is deformed or compressed causing the liquid layer to be squeezed or moved as the outer cover momentarily comes into contact with the inner core. This momentary contact causes the inner core to move or spin in synchronization with the outer layer, thereby defeating the purpose of the disjunction between the inner core and the outer layer.
Accordingly, it is seen that a need remains for a golf ball which has an outer layer which is disjoined from the inner core during all phases of flight. It is to the provision of such therefore that the present invention is primarily directed.
In a preferred form of the invention a golf ball comprises a spherical core, a spherical cover mounted concentrically about the core so as to define a spherical cavity therebetween, and a layer of unbound, granular particles positioned within the spherical cavity. With this construction, the layer of granular particles provides a disjunctive layer between the core and the cover.